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Chapter 18A is a Main Board chapter

Chapter 18A Biotech Companies sits within the Main Board Listing Rules. It is a dedicated chapter for biotech companies, not a separate “third tier” or third market.

The Exchange describes Chapter 18A as “a listing route for clinical-stage, pre-revenue biotech companies.” The chapter was introduced in 2018. Since its launch, 84 companies have listed via Chapter 18A, as of end-January 2026.

Chapter 18A therefore operates within Hong Kong’s Main Board framework while providing a route for companies that do not satisfy the ordinary financial eligibility tests applicable under Chapter 8. It is not an exemption from Main Board requirements as a whole.

Chapter 18A and the Chapter 8 Financial Eligibility Tests

Under Rule 18A.02, an applicant applying under Chapter 18A must satisfy Chapter 18A and Chapter 8, other than rules 8.05, 8.05A, 8.05B and 8.05C.

Main Board Listing Rule 18A.03(1) requires the applicant to demonstrate to the Exchange’s satisfaction that it is both eligible and suitable for listing as a Biotech Company.

HKEX-GL92-18 explains the relationship between Chapter 18A and the Chapter 8 financial tests. A Biotech Company that does not meet the profit test in Main Board Listing Rule 8.05(1), the market capitalisation/revenue/cash flow test in Main Board Listing Rule 8.05(2) or the market capitalisation/revenue test in Main Board Listing Rule 8.05(3) could be permitted to list under Chapter 18A.

HKEX-GL92-18 refers to those three tests collectively as the “Financial Eligibility Tests.” Chapter 18A provides a possible route for a company outside those tests, but the applicant must still satisfy Chapter 18A and the applicable remainder of Chapter 8. Eligibility under Chapter 18A is not automatic.

The suitability assessment is case by case

HKEX-GL92-18 states that an applicant “could be permitted” to list if it can demonstrate the required features. The language is permissive, not mandatory. Meeting the features does not itself entitle a company to list. Main Board Listing Rule 18A.03(1) still requires the Exchange to be satisfied that the applicant is eligible and suitable.

The suitability case must address, among other matters, sophisticated management and investors and a dedicated R&D team. The features identified in HKEX-GL92-18 include:

At least one Core Product developed beyond the concept stage. The applicable milestone depends on the type of product.
Primary engagement in research and development for the purposes of developing the Core Product(s).
Engagement in R&D of the Core Product(s) for a minimum of 12 months prior to listing.
A primary reason for listing of raising funds for R&D to bring the Core Product(s) to commercialisation.
Registered patent(s), patent application(s) and/or intellectual property relating to the Core Product(s).
Where the applicant is engaged in R&D of pharmaceutical (small molecule drugs) products or biologic products, a pipeline of those potential products.
Meaningful third party investment from at least one Sophisticated Investor.

These features form part of a suitability assessment. They should not be presented as a mechanical checklist that guarantees admission.

For a Core Product that has been in-licensed or acquired, HKEX-GL92-18 gives examples of R&D progress that may be demonstrated since the in-licensing or acquisition. Those examples include movement from the preclinical stage to the clinical stage, progression from one clinical phase to the next phase of clinical trial, or regulatory approval from the Competent Authority to market the Core Product.

“Beyond the concept stage”: the small-molecule evidence

The evidence for the product-stage requirement must be stated according to product type. For a new pharmaceutical (small molecule drug) Core Product, the applicant must demonstrate that it has completed Phase I clinical trials and that the relevant Competent Authority has no objection for it to commence Phase II (or later) clinical trials.

That is the specific milestone stated for a new pharmaceutical (small molecule drug) Core Product. It should not be generalised into a universal Phase I requirement for every Chapter 18A applicant or every Core Product. The evidence supplied for this article does not establish the corresponding milestones for other product types.

Sophisticated Investors and meaningful third party investment

The “meaningful third party investment” limb requires more than a token investment. The applicant must have received such investment from at least one Sophisticated Investor at least six months before the date of the proposed listing. The proposed listing must remain an IPO.

The Exchange assesses whether an investor is a Sophisticated Investor case by case. Relevant factors include net assets or assets under management, relevant investment experience, and the investor’s knowledge and expertise in the relevant field.

HKEX-GL92-18 gives four examples solely “for illustrative purposes only”:

A dedicated healthcare or Biotech fund, or an established fund with a division or department specialising or focused on biopharmaceutical investments.
A major pharmaceutical/healthcare company.
A venture capital fund of a major pharmaceutical/healthcare company.
An investor, investment fund or financial institution with minimum assets under management of HK$1 billion.

The HK$1 billion figure is therefore an example within the illustrative list. It is not a hard definition of a Sophisticated Investor.

The Exchange also assesses whether the investment is meaningful case by case. Relevant considerations include the nature of the investment, the amount invested, the size of the stake and the timing.

For an applicant with a market capitalisation between HK$1.5 billion to HK$3 billion, the indicative benchmark is an investment of not less than 5% of the issued share capital at the time of listing. For an applicant with a market capitalisation between HK$3 billion to HK$8 billion, the indicative benchmark is not less than 3%. For an applicant with a market capitalisation of more than HK$8 billion, the indicative benchmark is not less than 1%.

These percentages are the Exchange’s indicative benchmarks for meaningful third party investment, assessed case by case. They are not Chapter 18A listing thresholds.

For a spin-off from a parent company, the Exchange may not require compliance with the meaningful third party investment factor if the applicant can otherwise demonstrate a reasonable degree of market acceptance for its R&D and Biotech Product. Collaboration with other established R&D companies is given as an example of possible evidence.

Continuing obligations and the Stock Marker

The Chapter 18A architecture expressly includes disclosure in reports, sufficient operations, material changes and the Stock Marker. The Stock Marker is a distinct requirement under the chapter and should not be characterised as a lock-up.

These headings form part of the regime’s continuing-obligations structure. They should not be converted into numerical tests or post-listing restrictions that are not stated in the cited chapter material.

Chapter 18A and a US IPO

A Chapter 18A listing and a US IPO are separate routes in separate markets. Chapter 18A is a specialist route within the Hong Kong Main Board Listing Rules. It is not part of the US listing framework.

The Listing Rules cited do not establish equivalence, conversion or substitute eligibility between the two routes. Qualification for Chapter 18A does not establish eligibility for a US IPO. An issuer pursuing both routes must address the applicable requirements of each framework independently.